公开(公告)号：US20180094951A1

公开(公告)日：2018-04-05

申请号：US15834569

申请日：2017-12-07

Applicant: Allegro MicroSystems, LLC

Inventor： Simon Tima ,  Yannick Vuillermet ,  Andreas P. Friedrich ,  Thomas Kerdraon

IPC: G01D5/20 ,  G01R33/07 ,  G01B7/14

CPC classification number: G01D5/2013 ,  G01B7/14 ,  G01D5/147 ,  G01R33/072

Abstract: A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.

公开(公告)号：US20170234702A1

公开(公告)日：2017-08-17

申请号：US15042469

申请日：2016-02-12

Applicant: Allegro Microsystems, LLC

Inventor： Simon Tima ,  Yannick Vuillermet ,  Andreas P. Friedrich ,  Thomas Kerdraon

IPC: G01D5/20

CPC classification number: G01D5/2013 ,  G01B7/14 ,  G01D5/147 ,  G01R33/072

Abstract: A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.

公开(公告)号：US10598515B2

公开(公告)日：2020-03-24

申请号：US15834569

申请日：2017-12-07

Applicant: Allegro MicroSystems, LLC

Inventor： Simon Tima ,  Yannick Vuillermet ,  Andreas P. Friedrich ,  Thomas Kerdraon

IPC: G01B7/30 ,  G01D5/20 ,  G01D5/14 ,  G01B7/14 ,  G01R33/07

Abstract: A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.

公开(公告)号：US09869566B2

公开(公告)日：2018-01-16

申请号：US15042469

申请日：2016-02-12

Applicant: Allegro Microsystems, LLC

Inventor： Simon Tima ,  Yannick Vuillermet ,  Andreas P. Friedrich ,  Thomas Kerdraon

IPC: G01B7/30 ,  G01D5/20 ,  G01R33/07 ,  G01B7/14

CPC classification number: G01D5/2013 ,  G01B7/14 ,  G01D5/147 ,  G01R33/072

Abstract: A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.